curled up in a ball for a week and dropped off the radar, and she freaked out and then felt humiliated for giving a damn, and decided that she couldn't be doing with someone so unreliable. Which is fair enough, but rather gutting.
No. Not fair. Anyone who can't live without another person's surface to reflect off of for an entire week isn't a friend. A friend waits until you're ready to talk about it and then offers ice cream, chocolate and a good scotch. Unless there was more to it and I refuse to believe that because I have never seen you be anything less than generous and giving without even being asked. Give to me cluestick, I fix her.
Sail got here first. I'm sorry, but -- a week? *Only* a week? Your need to curl up in a ball -- mental health, emotional downtime, whatever you needed -- is WAY more important than your friend being humiliated because she worried about you. No offense intended to your friend, but -- WHO gets humiliated for worrying about someone? Even when it turns out that you didn't die/get kidnapped by Fay slavers/overdose, then what the concerned party says is, "Well, I'm glad you're okay, because my overprotective instincts kicked in! Want to get a martini and talk about it?"
What the friend *doesn't* do is make YOUR mental health about HER.
I'm sorry if I'm slagging on your good friend (or, I guess, ex-), but seriously, that is not appropriate behavior.
And I'm saying all that because it seems like your estimation of yourself has taken a few pokes in the eye over the past few months, and it just doesn't need to be so. These things -- your friend getting shirty, missing your Grand's birthday -- are emphatically NOT reasons to slag on yourself. Your friend behaved badly. You were not in the wrong there. And, seriously, *everyone* forgets their grandparents' birthdays now and again (some of us made it a yearly practice ::cough::).
You didn't punch your student in their wee faces, you didn't pee on the Thai flag or a photo of their King, you didn't abscond with the church funds or run off with a senator's wife. There is no need for you to be so hard on yourself. Your view of yourself as self-involved to the detriment of other people is simply not true.